...most ppl say it takes 55-60, i'm not sure why.
It's because that's what it takes most people on average.
Best guess: mainly a matter of age. Our experience is that students at an age of 16-19 are likely to finish within the minimum hours. Typical students are 35-45+ and it takes a bit longer, usually 50-65h. Some story behind is distraction due to many other things going on in a life of a 35-45 ... younger tend to focus more and they are trained to learn from school still.